A traditional elevator system for mid-rise and high-rise buildings includes a car and a counterweight interconnected by a rope and a traction machine engaged with the rope to drive the car and counterweight. The traction machine includes a sheave engaged with the rope, an electric motor for rotating the sheave, and a brake to hold the sheave when the car is stopped. The traction machine, along with an electronic controller for the elevator system and electronic drive for the machine, are housed in a machine-room located above the hoistway.
Various configurations have been suggested to eliminate the machine-room in an effort to save on the associated construction costs. One suggested elevator system uses a linear induction motor driven elevator; another uses a traction machine having a disc type motor mounted in the hoistway; and still another uses a self-propelled cab having a pinch-roller type drive engaged with the guide rails of the car.
While possibly saving construction costs of the building, an area of concern arises with such machine-roomless elevators in the event of an elevator shut-down. In a conventional elevator system having a machine-room, a mechanic may enter the machine-room and manually operate the traction machine to move the car to the nearest landing. Once there, the doors may be opened and the passengers evacuated. Due to the elimination of the machine-room in some of the suggested configurations, however, the traction machine may not be readily accessible. If a shut-down occurs, a mechanic may not be able to manually operate the traction machine.
The above art notwithstanding, scientists and engineers under the direction of Applicants' Assignee are working to develop simple and effective methods and apparatus to permit manual operation of elevator machines that are difficult to access due to their location.